Many heart rate sensors, both in clinical and in consumer applications, use the optical photoplethysmographic (PPG) method to extract the heart rate (HR) from the human body. The PPG method is based on the modulation of light parameters (reflection and/or absorption) when interacting with a blood vessel. Most clinical methods use light transmission through the finger. In consumer applications, the reflective method is typically used, for example by using PPG sensors in wristbands, watches, or cuffs worn at the upper arm. However, relative to chest strap monitors, PPG sensors typically suffer from reduced accuracy. As a result, improved methods and apparatuses for heart rate detection using PPG sensors are needed.